This invention pertains to watercraft of raft-like nature. More particularly, it pertains to an inflatable raft which has inherent self-righting properties; its uses include whitewater rafting.
Whitewater rafting is a sport and also a recreational activity. Many people participate in whitewater rafting as customers of businesses which own rafts on which, through guides, adventuresome customers pay to ride as the raft floats down a watercourse through rapids of varying degrees of hazard. In those instances where whitewater rafting is conducted as a business, as well as in the sporting context, it is important that the raft be as inherently safe as possible, while also providing to passengers a sense of exposure to hazard and danger.
Whitewater rafts commonly are inflatable watercraft. A widely used form of raft has a generally ringlike inflatable hull with generally parallel side portions between an arcuate stern and a generally pointed and upwardly sloped prow or forward end. In that form of raft, there is a fabric floor which spans the central opening in the hull and which is connected at its edges to the bottom extent of the annular hull substantially around the circumference of the hull. The passengers typically sit on or astride the side portions of the hull and paddle as directed by the guide to steer and turn the raft. While popular, rafts of the kind just described are subject to being overturned and to being caught in hydraulic reversals (also known as keepers, maytags or drowning machines)which keep the raft from moving downstream out of a hazardous situation. While not common, it is not unknown for participants in whitewater rafting to be seriously injured or even killed as a consequence of being thrown or dislodged from a raft.
A need exists for improved rafts which are inherently safer for passengers, but which do not so protect passengers that the desired sense of adventure and thrill is unduly dulled.
This invention beneficially addresses the need identified above. The invention provides a novel inflatable raft structure which has an inherent self-righting characteristic. Tests conducted with the new raft structure establish that it is very resistant to overturning and, if overturned, substantially self-rights itself automatically and quickly. Also, the hull is resistant to the effects of hydraulic reversals often encountered in rapids.
Generally speaking, a first form of raft of this invention comprises an elongate annular inflatable hull having a front end and a rear end and which is symmetrical about a hull vertical longitudinal center plane. The raft includes an inflatable righting structure extending centrally of the hull between the hull front and rear ends and disposed substantially above the hull at substantially the mid-length of the hull.
Also generally speaking, a second form of raft of this invention has an inflatable hull of substantially catamaran configuration. The hull is comprised of a pair of pontoons parallel to and on opposite sides of a hull vertical longitudinal center plane. Lower extents of the pontoons lie in a hull base plane. The hull also is comprised by forward and rear transverse bridges disposed substantially normal to the center plane with lower extents elevated above the base plane a distance greater than the design draft of the raft. The hull is further comprised by connecting sections inclined to the base plane and connecting forward and rear ends of the pontoons to the respective bridges.